adsense auto responsive code with fixed height

i am heaving problem with adsense responsive ad unit i want a rectangle on both mobile and desktop and when i use responsive ad unit it get rectangle on desktop but on mobile it becomes a square (50%+ of the mobile screen)
i tried putting it in a div with fixed height but it’s not working and i found this solutions but changing style tag but it’s not working either

    <ins class="adsbygoogle"
   style="display:inline-block;min-width:400px;max-width:970px;width:100%;height:90px"
   data-ad-client="ca-pub-1234"
   data-ad-slot="5678"></ins>
<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<script>(adsbygoogle = window.adsbygoogle || []).push({});</script>

i want a fix height so it’s rectangle on desktop and small rectangle on mobile